颗粒形貌对水泥性能的影响

ON INFLUENCE OF PARTICLE SHAPE OF CEMENT ON ITS PROPERTY

以多组水泥样品为对象,在控制其颗粒级配、比表面积基本一致的条件下,利用扫描电镜等测试手段,研究水泥颗粒形貌改善对水泥性能及孔结构等的影响。结果表明:水泥颗粒形貌改善后,水泥胶砂流动度随水泥颗粒形貌的改善而不断增大。水泥凝结时间略有延长,水泥颗粒粉状物料堆积状况更趋密实。水泥胶砂试体中总孔隙率降低,中位孔径及平均孔径减小。在相同砂浆流动度下,颗粒形式改善后水泥的圆形系数由0.67提高至0.72,水灰比可减少8%,各龄期水泥抗压强度均提高20%以上。在相同水灰比下,圆形系数的平均值由0.65提高至0.73,水泥中后期抗压强度平均增长10%～12%。

Influence of particle shape of cement on its physical properties was studied by means of SEM and pore structure analysis. Particle distribution and similar specific surface area are very important in the preparation of samples. The results show that the fluidity of cement mortar becomes higher, the setting time of cement is longer, and the stack of cement particle is much tighter because of the improvement of cement particle shape, at the same time the total porosity of the hydrating cement mortar becomes lower, and the pore diameters are well distributed. When the fluidity of cement mortar keeps at the same level, the water-cement ratio of the improved particle shape sample decreases by 8%, and the compressive strength increases by 20% at each age, and the degree of roundness raises to 0.72 from 0.67. If the water-cement ratio is in the same value, the compressive strength increases by 10%-12% while the degree of roundness raises to 0.73 from 0.65.